[Discussion on the expression of retention factor in capillary electrochromatography]

On the assumption that the component electrophoresis factor does not have parametric interaction with its chromatographic behavior in capillary electrochromatography, two new retention factor expressions k*CEC = k' - microep/microeo + microep (I) and k**CEC = k'microep - micro(0)ep/microeo + microep (II) are deduced, and they are complementary to each other. Two expressions of component retention factor in the literature, kCEC = k' + k' (microep + microep/microeo + microeo (III) and kCEC = k' microep/microeo/1 + microep/microeo (IV), are discussed. Wrong citation of the component electrophoresis migration distance expression in the deduction of expression (III) is pointed out. But the expressions (I) and (IV) also can't reflect the influences of microep and k' on kCEC under some conditions. The expression (II) can make up the limitation of the above expressions, especially when microeo = 0. Expressions (I) and (II) can reflect the integrated effect of component chromatographic and electrophoretic behaviors.